Synthesis and characterization of variously asymmetrically chloro-substituted disilanes and trisilanes - A new perspective on known compounds

Abstract Asymmetrically phenyl-substituted disilanes of the general formula RMe₂Si-SiMePh₂ (MPD02: R = Me, MPD12: R = Ph) and the trisilane (PhMe₂Si)₂SiMePh (MPT111) were prepared from the corresponding monosilanes using lithium as coupling reagent. These compounds were utilized as precursors for the preparation of the chlorosilanes Cl₂MeSi-SiMe₂R (CMD20: R = Me; CMD21: R = Cl) and (ClMe₂Si)₂SiMeCl (CMT111). The phenyl groups were selectively removed using acetyl chloride and anhydrous AlCl₃. Subjecting these phenyl-substituted methyloligosilanes to the redesigned literature-known reaction conditions, the strengths of the synthetic routes shown so far were combined. In addition, not only methyl-substituents are applicable, since we used Ph₂(tBu)Si-SiMe₂Ph (tBuMPD21) as precursor for the preparation of Cl₂(tBu)Si-SiMe₂Cl (tBuCMD21). The characterization of the phenyl- and chloro-substituted di- and trisilanes mentioned above is not completely reported in literature. They were fully analyzed by means of NMR and IR spectroscopy, GC-MS, DSC and elemental analysis at our chair. DSC studies of the synthesized chlorosilanes led to the assumption of a plastic crystalline behavior for certain compounds. Beyond that, CV measurements of the chloro-substituted compounds pointed out that their reduction occurs at highly negative potentials.